'To Catch a Predator' IIIChris Hansen reports on the "Dateline NBC" continuing investigation of Internet sex predators. Watch a preview of the third installment, based on the West coast, where cameras— and cops— capture more men looking to have sex with minors. Full report airs February 3, Friday, 9 p.m.

From Senior Producer, Broadcast Standards Lisa Green: As viewers demand more transparency from journalists, it’s especially important that we explain why we think hidden camera is an important part of our work.